1. Field of the Invention
The invention relates to a door lock, more particularly to a tubular lock that incorporates an electrically operated driving wheel to control the latching and unlatching operations of the tubular lock.
2. Description of the Related Art
Various forms of tubular locks have existed in the art. FIG. 1 shows a typical tubular lock 10 which comprises an outer handle body 11 adapted to be mounted on the outer side of a door, and an inner handle body 12 adapted to be mounted on the inner side of the door. The outer and inner handle bodies 11 and 12 are interconnected by a spindle 13 which passes through a spindle hole of a latch mechanism (not shown) and which incorporates a mandrel 131 therein. The mandrel 131 is connected to a knob body 121 disposed inside the inner handle body 12. The spindle 13 also passes through a spindle hole 123 of a rotatable hollow cylinder 122. When the knob body 121 is turned manually, the mandrel 131 will move a locking element (not shown) disposed in the outer handle body 11 so that the hollow cylinder 122 and the spindle 13 are locked against rotation. In this situation, the tubular lock 10 is in a locked position. If the mandrel 131 is turned in a reversed direction, the locking element is moved to a releasing position, thereby releasing the cylinder 122 and the spindle 13 and unlocking the tubular lock 10. On the other hand, when the handle body 12 is rotated, the cylinder 122 and the spindle 13 can be turned to actuate the latch mechanism so that the door can be latched or unlatched. As mentioned hereinabove, conventional tubular locks generally comprise a mandrel and a spindle which interconnect inner and outer handle bodies or levers and which are operable only through a manual operation. Improvements are therefore desirable so as to render conventional tubular locks operable via electric means.